In vacuum systems it is often necessary to form a sealed connection between two parts, or devices. For example, a vacuum pump may be connected with an analysing device such as a mass spectrometer. The vacuum pump may be used to evacuate one or more chambers in the mass spectrometer and this requires a sealed connection(s) between the vacuum pump and the mass spectrometer.
FIG. 1 is a perspective view of a turbo molecular pump 10 that may be connected to a mass spectrometer to evacuate a plurality of chambers in the mass spectrometer, for example as disclosed in WO2006/000745. The pump 10 comprises a pump body 12 provided with a flange 14. The flange 14 has a planar face 16 provided with grooves 18 for respective sealing elements, such as O-rings. The flange 14 is provided with a plurality of apertures 20 through which respective fastening elements, for example bolts, can be inserted into respective threaded apertures provided in a flange or other planar surface of the mass spectrometer. The longitudinal axis of the fastening elements extends perpendicular to the plane of the planar face 16.
The pump 10 may be located on the underside of, or other locations on, the mass spectrometer that are relatively difficult to access. This may give rise to difficulties both at the initial installation stage and subsequently in the event the pump requires replacement or repair, or the sealing element between the pump and mass spectrometer requires replacement. It is also necessary to perform individual tightening operations to tighten and secure each bolt, which can be particularly time-consuming if the bolt heads are difficult to access.